This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Background: A study was conducted on captive rhesus macaque (Macaca mulatta) to estimate heritability of a number of reproductive parameters. Methods: Reproductive records from a colony of Indian rhesus macaques were available from the years 1970 to 2008. A total of 3,569 females produced 16,006 birth records during this period. Records included identification of female and infant, but not the male parent of the infant. All reproductive records were assumed to be a function of the female genotype. Therefore, identification of the dam of each female resulted in maternal half-sib families with the grand dam as the common parent. A total of 1,300 grand dams were identified in the data set. A total of 9,010 records from 2,081 dams had grand dam identification. Results/Discussion: The statistical model for each dam response included grand dam as a random source of variation and various fixed sources of variation that were found to influence variation in the particular response. The standard error of each heritability estimate was determined using [unreadable]32*h2 /N where N is the number of records analyzed for that trait and 32*h2 /N is an estimate of the variance of heritability. Coefficients of heritability of lifetime productivity proved to be moderate. These included a female's age at death (h2 = 0.60[unreadable] 0.11), her age at her last birth (h2 = 0.68 [unreadable] 0.12) and the number of infants produced during her lifetime (h2 = 0.61 [unreadable] 0.11). In contrast, traits such as postpartum age at first birth (h2 = 0.24 [unreadable] 0.06), birth interval (h2 = 0.15 [unreadable] 0.03), survival of the infant to 30 days (h2 = 0.14 [unreadable] 0.02) and 1 year (h2 = 0.06 [unreadable] 0.02) had very low heritability coefficients. Heritability estimates in association with behavioral data may provide useful tools in management of breeding colonies, particularly for the selection and retention of breeding females.